1. Field of the Invention
The present invention relates to an optical pickup device and more particularly, it relates to an optical pickup device which is used as a pickup device in a CD player for reproducing optical information on a recording medium.
2. Description of the Prior Art
A conventional optical pickup device disclosed in U.S. Pat. Nos. 4,678,276 and 4,473,274 reads a signal with micro light beam. In such a device, an objective lens of the optical pickup device is mechanically moved in a focusing direction and a tracking direction, for example, by a two-shaft actuator in order to read a signal with high accuracy, and thereby the focus of light beam follows a signal arranged on a track on a recording medium.
However, it is necessary to use a lot of precision machine parts to move the objective lens mechanically with high accuracy. As a result, an optical system has a large-size and its weight is also increased. In addition to that, its manufacturing process is complicated to cause an increase in manufacturing cost. Also, dust laying on the precision machine parts makes operation unstable, and therefore the maintenance of the device is difficult.